The present invention relates to an apparatus for controlling the paper feed operation in a printer, and, in particular, to a device and method for controlling a paper feed motor which operates in response to control commands from a host computer.
An apparatus for controlling a paper feed motor of a printer is known in the art. The conventional device receives control commands which are output in succession from a host computer. This causes a conventional printer to repeat a motor driving pattern as shown in FIG. 1 of the drawings in which the motor is accelerated in a time region a, driven at a constant speed in time region b, decelerated during a time period c and stops during a time period d. A paper feed motor ("PF motor") is driven in accordance with each control command. In order to print within a paper space which is suitable for printing, at the end of each series of paper feeding commands, it is determined whether printing is currently being conducted within the printable area. Once this judgement is made, a subsequent print and feed operation is executed in sequence as above as long as it is determined after each sequence that printing is still occurring within the printable area.
The conventional paper feed devices have been satisfactory. However, it becomes necessary to conduct motor acceleration in time period a, constant speed operation in time period b, deceleration in time period c and stopping of the motor in time period d for the PF motor each time the control commands are input from the host computer and then repeat them for each successive line. Accordingly, an unnecessary amount of time for acceleration and deceleration is repeatedly utilized for each line. The unnecessary time increases in proportion to an increase in the number of lines to be repeated. This reduces the actual printing speed of the printer which depends on the driving time of the PF motor.
Accordingly, it desired to provide a paper feed control device and method which eliminates this waste of time, thereby improving actual printing speed of the printer by accumulating the paper feed amount specified by the control commands and then utilizing this accumulated value at a specified time.